Abstract The incidence rate for testicular cancer in Utah is the highest of all the cancer registries in the United States (8.3 per 100,000 in 2007). On a worldwide level, approximately 52,549 cases and 9,906 deaths occur due to testicular cancer each year. It is one of the few cancers with increasing incidence over the last few decades in the US and Europe. In Utah, the age-adjusted incidence rates for men aged 15-49 years increased from 6.4 in 1973 to 13.8 in 2007. The five year survival among testicular cancer patients in the US was 96.0% for men >20 years old (1988-2001). The well-established testicular cancer risk factors include age, contralateral testicular cancer, cryptorchidism, race/ethnicity and family history of testicular cancer. Other factors that have been examined but have led to conflicting results across studies include lower birth order, higher maternalage, short gestational duration, and low birth weight. Thus far, an epidemiologic study on testicular cancer in Utah has never been conducted. The Utah Population Database (UPDB) is an existing data source that provides an excellent opportunity to examine testicular cancer trends, risk factors and prognosis in Utah. It has been used in various gene identifying and familial clustering studies for breast cancer, colorectal cancer, melanoma and prostate cancer, but this will be the first application of using this database for studying testicular cancer risk factors. Additionally, the UPDB has been used to study prenatal factors from birth certificate records as possible risk factors for outcomes such as preterm births and autism spectrum disorders, but prenatal factors have not been studied for any cancers thus far in the UPDB. The UPDB has over 14.5 million records with linkage across cancer registry data, birth certificate records, death records, driver's license records, and medical records. We also have access to geocoded data on proximity to specific agricultural activities (as a proxy for pesticide exposure) and exposure to contaminants in drinking water in Utah, which will be linked to the UPDB records. We propose to conduct the following studies within the UPDB: 1) a descriptive epidemiology of testicular cancers, 2) a population-based case-control study, and 3) a follow up study of testicular cancer patients. We expect to include approximately 1,826 testicular cancer patients (1973-2007) for the descriptive epidemiology and follow up studies. For the case-control study, we will include 1,826 testicular cancer patients and 5,478 controls (3 controls per case). Our specific aims are in parallel to the study designs: 1) to investigate the testicular cancer trends for the Utah population, 2) to examine prenatal and perinatal factors, history of previous disease, family history of cancer, and rural residence as possible risk factors for testicular cancer, and 3) to study survival, and incidence of second primary tumors, cardiovascular disease, depression and other diseases among testicular cancer patients in Utah. This study will be the first epidemiologic study of testicular cancer in Utah. We will take advantage of a unique existing data resource to contribute to a better understanding of testicular cancer in Utah. PUBLIC HEALTH RELEVANCE: PROJECT NARRATIVE Our project on testicular cancer in Utah is important for public health because it will contribute to a better understanding of the trends over time and the risk factors are important for testicular cancer in this high risk population. We will also study the prognosis of testicular cancer patients and examine what factors affect prognosis. Our results will be relevant for public health planning of prevention efforts against testicular cancer in Utah.